Although the cell membrane is a complex structure, its basic form, and the self-organizing behavior of the molecules that produce it, can be easily simulated in a high school science classroom. One such simulation, described in this article, uses oil, water, and the cell membrane-forming molecules (phospholipids) of egg yolk. The demonstration allows students to observe the self-assembly of phospholipid membranes around oil and water droplets, which shows how easily polar forces help construct then hold together the cell membranes in living organisms.